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<h2><a name="apply">Apply/<i>ExecOn</i></a></h2>
<p><i>The name <code>execon</code> is deprecated and only kept for backwards
compatibility.</i></p>
<h3>Description</h3>
<p>Executes a system command. When the <i>os</i> attribute is specified, then
the command is only executed when Apache Ant is run on one of the specified operating
systems.</p>

<p>The files and/or directories of a number of <a
href="../Types/resources.html#collection">Resource Collection</a>s
&ndash; including but not restricted to
 <a href="../Types/fileset.html">FileSet</a>s,
 <a href="../Types/dirset.html">DirSet</a>s
 (<em>since&nbsp;Ant&nbsp;1.6</em>) or
 <a href="../Types/filelist.html">FileList</a>s
 (<em>since&nbsp;Ant&nbsp;1.6</em>)
&ndash;
 are passed as arguments to the system command.</p>
<p>If you specify a nested <a href="../Types/mapper.html">mapper</a>,
the timestamp of each source file is compared to the timestamp of a
target file which is defined by the nested mapper element and searched
for in the given <i>dest</i>, if specified.</p>
<p>At least one fileset or filelist is required,
and you must not specify more than one mapper.</p>

<p>Note that you cannot interact with the forked program, the only way
to send input to it is via the input and inputstring attributes.</p>

<h4><a name="background">Running Ant as a background process on
    Unix(-like) systems</a></h4>

<p>If you run Ant as a background process (like <code>ant &</code>)
  and use the <code>&lt;apply&gt;</code> task with <code>spawn</code>
  set to <code>false</code>, you must provide explicit input to the
  forked process or Ant will be suspended because it tries to read
  from the standard input.</p>

<h3>Parameters</h3>
<table border="1" cellpadding="2" cellspacing="0">
  <tr>
    <td valign="top"><b>Attribute</b></td>
    <td valign="top"><b>Description</b></td>
    <td align="center" valign="top"><b>Required</b></td>
  </tr>
  <tr>
    <td valign="top">executable</td>
    <td valign="top">the command to execute without any command line
      arguments.</td>
    <td align="center" valign="top">Yes</td>
  </tr>
  <tr>
    <td valign="top">dest</td>
    <td valign="top">the directory where the command is expected to place
    target files when it is executed. This attribute is valid only when used
    in conjunction with a nested mapper; if omitted, the target filenames
    returned by the mapper will be interpreted as absolute paths.</td>
    <td align="center" valign="top">No</td>
  </tr>
  <tr>
    <td valign="top">spawn</td>
    <td valign="top">whether or not you want the commands to be spawned.<br>
    If you spawn a command, its output will not be logged by ant.<br>
    The input, output, error, and result property settings are not active when spawning a process.<br>
    <em>since&nbsp;Ant&nbsp;1.6</em>
    </td>
    <td align="center" valign="top">No, default is <i>false</i></td>
  </tr>

  <tr>
    <td valign="top">dir</td>
    <td valign="top">the directory in which the command should be executed.</td>
    <td align="center" valign="top">No</td>
  </tr>
  <tr>
    <td valign="top">relative</td>
    <td valign="top">whether the filenames should be passed on the
      command line as relative pathnames (relative to the base directory
      of the corresponding fileset/list for source files or the
      <i>dest</i> attribute for target files).</td>
    <td align="center" valign="top">No, default is <i>false</i></td>
  </tr>
  <tr>
    <td valign="top">forwardslash</td>
    <td valign="top">whether the file names should be passed
      with forward slashes even if the operating system requires other
      file separator. The option is ignored if the system file separator
      is a forward slash.</td>
    <td align="center" valign="top">No, default is <i>false</i></td>
  </tr>
  <tr>
    <td valign="top">os</td>
    <td valign="top">list of Operating Systems on which the command may be
      executed.</td>
    <td align="center" valign="top">No</td>
  </tr>
  <tr>
    <td valign="top">osfamily</td>
    <td valign="top">OS family as used in the &lt;os&gt; condition.
    <em>since Ant 1.7</em></td>
    <td align="center" valign="top">No</td>
  </tr>
  <tr>
    <td valign="top">output</td>
    <td valign="top">the file to which the output of the command
    should be redirected.  If the error stream is not also redirected
    to a file or property, it will appear in this output.</td>
    <td align="center" valign="top">No</td>
  </tr>
  <tr>
    <td valign="top">error</td>
    <td valign="top">The file to which the standard error of the
    command should be redirected.  <em>since&nbsp;Ant&nbsp;1.6</em></td>
    <td align="center" valign="top">No</td>
  </tr>
  <tr>
    <td valign="top">logError</td>
    <td valign="top">This attribute is used when you wish to see error
    output in Ant's log and you are redirecting output to a
    file/property. The error output will not be included in the output
    file/property. If you redirect error with the &quot;error&quot; or
    &quot;errorProperty&quot; attributes, this will have no effect.
    <em>since&nbsp;Ant&nbsp;1.6</em></td>
    <td align="center" valign="top">No</td>
  </tr>
  <tr>
    <td valign="top">append</td>
    <td valign="top">whether output should be appended to or overwrite
      an existing file.  If you set parallel to false, you will probably
      want to set this one to true.</td>
    <td align="center" valign="top">No, default is <i>false</i></td>
  </tr>
  <tr>
    <td valign="top">outputproperty</td>
    <td valign="top">the name of a property in which the output of the
    command should be stored.  Unless the error stream is redirected
    to a separate file or stream, this property will include the error
    output.</td>
    <td align="center" valign="top">No</td>
  </tr>
  <tr>
    <td valign="top">errorproperty</td>
    <td valign="top">The name of a property in which the standard error of the
      command should be stored.  <em>since&nbsp;Ant&nbsp;1.6</em></td>
    <td align="center" valign="top">No</td>
  </tr>
  <tr>
    <td valign="top">input</td>
    <td valign="top">A file from which the executed command's standard
    input is taken. This attribute is mutually exclusive with the
    inputstring attribute.  <em>since&nbsp;Ant&nbsp;1.6</em></td>
    <td align="center" valign="top">No</td>
  </tr>
  <tr>
    <td valign="top">inputstring</td>
    <td valign="top">A string which serves as the input stream for the
    executed command. This attribute is mutually exclusive with the
    input attribute.  <em>since&nbsp;Ant&nbsp;1.6</em></td>
    <td align="center" valign="top">No</td>
  </tr>
  <tr>
    <td valign="top">resultproperty</td>
    <td valign="top">the name of a property in which the return code
      of the command should be stored. Only of interest if
      failonerror=false. If you set parallel to false, only the result
      of the first execution will be stored.</td>
    <td align="center" valign="top">No</td>
  </tr>
  <tr>
    <td valign="top">timeout</td>
    <td valign="top">Stop the command if it doesn't finish within the
      specified time (given in milliseconds).</td>
    <td align="center" valign="top">No</td>
  </tr>
  <tr>
    <td valign="top">failonerror</td>
    <td valign="top">Stop the buildprocess if the command exits with a
      returncode other than 0.</td>
    <td align="center" valign="top">No</td>
  </tr>
  <tr>
    <td valign="top">failifexecutionfails</td>
    <td valign="top">Stop the build if we can't start the program.
      Defaults to true. </td>
    <td align="center" valign="top">No</td>
  </tr>
  <tr>
    <td valign="top">skipemptyfilesets</td>
    <td valign="top">Don't run the command, if no source files have
      been found or are newer than their corresponding target
      files.  Despite its name, this attribute applies to filelists as
      well.</td>
    <td align="center" valign="top">No, default is <i>false</i></td>
  </tr>
  <tr>
    <td valign="top">parallel</td>
    <td valign="top">Run the command only once, appending all files as
      arguments. If false, command will be executed once for every file.</td>
    <td align="center" valign="top">No, default is <i>false</i></td>
  </tr>
  <tr>
    <td valign="top">type</td>
    <td valign="top">One of <i>file</i>, <i>dir</i> or
      <i>both</i>. If set to <i>file</i>, only the names of plain
      files will be sent to the command. If set to <i>dir</i>, only
      the names of directories are considered.<br>
      <strong>Note:</strong> The type attribute does not apply to
      nested <i>dirset</i>s - <i>dirset</i>s always implicitly
      assume type to be <i>dir</i>.</td>
    <td align="center" valign="top">No, default is <i>file</i></td>
  </tr>
  <tr>
    <td valign="top">newenvironment</td>
    <td valign="top">Do not propagate old environment when new environment
      variables are specified.</td>
    <td align="center" valign="top">No, default is <i>false</i></td>
  </tr>
  <tr>
    <td valign="top">vmlauncher</td>
    <td valign="top">Run command using the Java VM's execution facilities
        where available. If set to false the underlying OS's shell,
        either directly or through the antRun scripts, will be used.
        Under some operating systems, this gives access to facilities
        not normally available through the VM including, under Windows,
        being able to execute scripts, rather than their associated
        interpreter.  If you want to specify the name of the
        executable as a relative path to the directory given by the
        dir attribute, it may become necessary to set vmlauncher to
        false as well.</td>
    <td align="center" valign="top">No, default is <i>true</i></td>
  </tr>
  <tr>
    <td valign="top">resolveExecutable</td>
    <td valign="top">When this attribute is true, the name of the
    executable if resolved firstly against the project basedir and if
    that does not exist, against the execution directory if
    specified. On Unix systems, if you only want to allow execution of
    commands in the user's path, set this to false.
    <em>since&nbsp;Ant&nbsp;1.6</em></td>
    <td align="center" valign="top">No, default is <i>false</i></td>
  </tr>
  <tr>
    <td valign="top">maxparallel</td>
    <td valign="top">Limit the amount of parallelism by passing at
      most this many sourcefiles at once.  Set it to &lt;= 0 for
      unlimited. <em>Since&nbsp;Ant&nbsp;1.6.</em></td>
    <td align="center" valign="top">No, unlimited by default</td>
  </tr>
  <tr>
    <td valign="top">addsourcefile</td>
    <td valign="top">Whether source file names should be added to the
      command automatically. <em>Since&nbsp;Ant&nbsp;1.6.</em></td>
    <td align="center" valign="top">No, default is <i>true</i></td>
  </tr>
  <tr>
    <td valign="top">verbose</td>
    <td valign="top">Whether to print a summary after execution or not.
      <em>Since&nbsp;Ant&nbsp;1.6.</em></td>
    <td align="center" valign="top">No, default <i>false</i></td>
  </tr>
  <tr>
    <td valign="top">ignoremissing</td>
    <td valign="top">Whether to ignore nonexistent files specified
      via filelists.  <em>Since&nbsp;Ant&nbsp;1.6.2.</em></td>
    <td align="center" valign="top">No, default is <i>true</i></td>
  </tr>
  <tr>
    <td valign="top">force</td>
    <td valign="top">Whether to bypass timestamp comparisons
      for target files.  <em>Since&nbsp;Ant&nbsp;1.6.3.</em></td>
    <td align="center" valign="top">No, default is <i>false</i></td>
  </tr>
</table>
<h3>Parameters specified as nested elements</h3>
<h4>fileset</h4>
<p>You can use any number of nested <code>&lt;fileset&gt;</code>
elements to define the files for this task and refer to
<code>&lt;fileset&gt;</code>s defined elsewhere.</p>
<h4>filelist</h4>
<p><em>Since&nbsp;Ant&nbsp;1.6</em></p>
<p>You can use any number of nested <code>&lt;filelist&gt;</code>
elements to define the files for this task and refer to
<code>&lt;filelist&gt;</code>s defined elsewhere.</p>
<h4>dirset</h4>
<p><em>Since&nbsp;Ant&nbsp;1.6</em></p>
<p>You can use any number of nested <code>&lt;dirset&gt;</code>
elements to define the directories for this task and refer to
<code>&lt;dirset&gt;</code>s defined elsewhere.</p>

<h4>Any other <a href="../Types/resources.html#collection">Resource
Collection</a></h4>
<p><em>since Ant 1.7</em></p>
<p>You can use any number of nested resource collections.</p>

<h4>mapper</h4>
<p>A single <code>&lt;mapper&gt;</code> specifies the target files relative
to the <code>dest</code> attribute for dependency checking. If the
<code>dest</code> attribute is specified it will be used as a base directory
for resolving relative pathnames returned by the mapper. At least one
<code>&lt;fileset&gt;</code> or <code>&lt;filelist&gt;</code> is required.</p>
<h4>arg</h4>
<p>Command line arguments should be specified as nested
<code>&lt;arg&gt;</code> elements. See <a
href="../using.html#arg">Command line arguments</a>.</p>
<h4>srcfile</h4>
<p>By default the file names of the source files will be added to the
end of the command line (unless you set addsourcefile to
<code>false</code>). If you need to place it somewhere different,
use a nested <code>&lt;srcfile&gt;</code> element between your
<code>&lt;arg&gt;</code> elements to mark the insertion point.</p>
<table border="1" cellpadding="2" cellspacing="0">
  <tr>
    <td valign="top"><b>Attribute</b></td>
    <td valign="top"><b>Description</b></td>
    <td align="center" valign="top"><b>Required</b></td>
  </tr>
  <tr>
    <td valign="top">prefix</td>
    <td valign="top">a prefix to place in front of the file name when
    building the command line argument.  <em>Since Ant 1.8.0</em></td>
    <td align="center" valign="top">No.</td>
  </tr>
  <tr>
    <td valign="top">suffix</td>
    <td valign="top">a suffix to append to the file name when
    building the command line argument.  <em>Since Ant 1.8.0</em></td>
    <td align="center" valign="top">No.</td>
  </tr>
</table>
<h4>targetfile</h4>
<p><code>&lt;targetfile&gt;</code> is similar to
<code>&lt;srcfile&gt;</code> and marks the position of the target
filename on the command line. If omitted, the target filenames will
not be added to the command line at all. This element can only be
specified if you also define a nested mapper.</p>
<table border="1" cellpadding="2" cellspacing="0">
  <tr>
    <td valign="top"><b>Attribute</b></td>
    <td valign="top"><b>Description</b></td>
    <td align="center" valign="top"><b>Required</b></td>
  </tr>
  <tr>
    <td valign="top">prefix</td>
    <td valign="top">a prefix to place in front of the file name when
    building the command line argument.  <em>Since Ant 1.8.0</em></td>
    <td align="center" valign="top">No.</td>
  </tr>
  <tr>
    <td valign="top">suffix</td>
    <td valign="top">a suffix to append to the file name when
    building the command line argument.  <em>Since Ant 1.8.0</em></td>
    <td align="center" valign="top">No.</td>
  </tr>
</table>
<h4>env</h4>
<p>It is possible to specify environment variables to pass to the
system command via nested <code>&lt;env&gt;</code> elements. See the
description in the section about <a href="exec.html#env">exec</a></p>
<h4>redirector</h4>
<i><b>Since&nbsp;Ant&nbsp;1.6.2</b></i>
<p>A nested <a href="../Types/redirector.html">I/O Redirector</a>
can be specified.  &lt;apply&gt;'s behavior is like that of
<a href="exec.html#redirector">exec</a> with regard to
redirectors, with the exception that, in non-<i>parallel</i> mode,
file mapping will take place with each iteration.  This grants the
user the capacity to receive input from, and send output to, different
files for each sourcefile.
</p>
<p>In <i>parallel</i>-mode the redirector will be reset for each batch
  of executions (with <i>maxparallel</i> &gt; 0) and null will be used
  a source file just like it is in the case of <code>exec</code>.</p>
<h3>Examples</h3>
<blockquote><pre>
&lt;apply executable=&quot;ls&quot;&gt;
  &lt;arg value=&quot;-l&quot;/&gt;
  &lt;fileset dir=&quot;/tmp&quot;&gt;
    &lt;patternset&gt;
      &lt;exclude name=&quot;**/*.txt&quot;/&gt;
    &lt;/patternset&gt;
  &lt;/fileset&gt;
  &lt;fileset refid=&quot;other.files&quot;/&gt;
&lt;/apply&gt;
</pre></blockquote>
<p>invokes <code>ls -l</code>, adding the absolute filenames of all
files below <code>/tmp</code> not ending in <code>.txt</code> and all
files of the FileSet with <code>id</code> <code>other.files</code> to
the command line.</p>
<blockquote><pre>
&lt;apply executable=&quot;somecommand&quot; parallel=&quot;false&quot;&gt;
  &lt;arg value=&quot;arg1&quot;/&gt;
  &lt;srcfile/&gt;
  &lt;arg value=&quot;arg2&quot;/&gt;
  &lt;fileset dir=&quot;/tmp&quot;/&gt;
&lt;/apply&gt;
</pre></blockquote>
<p>invokes <code>somecommand arg1 SOURCEFILENAME arg2</code> for each
file in <code>/tmp</code> replacing SOURCEFILENAME with the absolute
filename of each file in turn. If <code>parallel</code> had been set
to true, SOURCEFILENAME would be replaced with the absolute filenames
of all files separated by spaces.</p>
<blockquote><pre>
&lt;apply executable=&quot;cc&quot; dest=&quot;src/C&quot; parallel=&quot;false&quot;&gt;
  &lt;arg value=&quot;-c&quot;/&gt;
  &lt;arg value=&quot;-o&quot;/&gt;
  &lt;targetfile/&gt;
  &lt;srcfile/&gt;
  &lt;fileset dir=&quot;src/C&quot; includes=&quot;*.c&quot;/&gt;
  &lt;mapper type=&quot;glob&quot; from=&quot;*.c&quot; to=&quot;*.o&quot;/&gt;
&lt;/apply&gt;
</pre></blockquote>
<p>invokes <code>cc -c -o TARGETFILE SOURCEFILE</code> for each
<code>.c</code> file that is newer than the corresponding
<code>.o</code>, replacing TARGETFILE with the absolute filename of
the <code>.o</code> and SOURCEFILE with the absolute name of the
<code>.c</code> file.</p>
<blockquote><pre>
&lt;mapper id=&quot;out&quot; type=&quot;glob&quot;
           from=&quot;src${file.separator}*.file&quot;
           to=&quot;dest${file.separator}*.out&quot;/&gt;

&lt;apply executable=&quot;processfile&quot; dest=&quot;dest&quot;&gt;
  &lt;fileset dir=&quot;src&quot; includes=&quot;*.file&quot;/&gt;
  &lt;mapper refid=&quot;out&quot;/&gt;
  &lt;redirector&gt;
    &lt;outputmapper refid=&quot;out&quot;/&gt;
  &lt;/redirector&gt;
&lt;/apply&gt;
</pre></blockquote>
Applies the fictitious &quot;processfile&quot; executable to all
files matching <code>*.file</code> in the <code>src</code> directory.
The <code>out</code> <code>&lt;mapper&gt;</code> has been set up to map
<code>*.file</code> to <code>*.out</code>, then this <code>&lt;mapper&gt;</code>
is used to specify <code>targetfile</code>s for this &lt;apply&gt;
task.  A reference to <code>out</code> is then used as an
<code>&lt;outputmapper&gt;</code> nested in a <code>&lt;redirector&gt;</code>, which in turn is
nested beneath this <code>&lt;apply&gt;</code> instance.  This allows us to perform
dependency checking against output files--the target files in this case.
<blockquote><pre>
&lt;apply executable="ls" parallel="true"
       force="true" dest="${basedir}" append="true" type="both"&gt;
  &lt;path&gt;
    &lt;pathelement path="${env.PATH}"/&gt;
  &lt;/path&gt;
  &lt;identitymapper/&gt;
&lt;/apply&gt;
</pre></blockquote>
Applies the "ls" executable to all directories in the PATH, effectively
listing all executables that are available on the PATH.

<blockquote><pre>
&lt;apply executable="jsmin" addsourcefile="false"&gt;
    &lt;!-- Collect the JS-files --&gt;
    &lt;fileset dir="src" includes="*.js"/&gt;
    &lt;redirector&gt;
        &lt;!-- redirect STDIN; fileset collects relative to its dir, but we need --&gt;
        &lt;!-- relative to basedir --&gt;
        &lt;inputmapper type="glob" from="*" to="src/*"/&gt;
        &lt;!-- redirect STDOUT to file in dest-dir --&gt;
        &lt;outputmapper id="out" type="glob" from="*.js" to="dest/*.js"/&gt;
    &lt;/redirector&gt;
&lt;/apply&gt;
</pre></blockquote>
Conversion of the command <code>jsmin &lt; src/a.js &gt; dest/a.js</code> but for
all files in the src-directory. Because the filename itself should not be passed
to the <code>jsmin</code> program, the <code>addsourcefile</code> is set to
<code>false</code>.






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